[Question #5704] NGU or false negative?

19 months ago

Hello, and thank you for this valuable service you provide the public.

Roughly 2 weeks ago, I had an encounter with an escort in the USA.  She is visiting from Russia, which I've learned has a higher rate of STIs than Western countries.  We engaged in light kissing (w/out tongue), unprotected oral sex (mutual), and fully protected vaginal sex to completion. I am 100% certain the condom was used throughout the event and did not break.

72 hours later, I noticed yellow/green spots on my underwear and thick discharge from my penis. I went immediately to a clinic, where the Dr. took a urine sample and informed me that the protocol was to provide a shot of Rocephin and 4 simultaneous azithromycin pills.  The discharge cleared up entirely within 8-12 hours I’d estimate. The gonorrhea amplification and chlamydia amplification tests were negative. (Also, I did not urinate within 1-2 hrs of providing the sample, which I'm told can affect results).  The Dr. determined this was likely GCU, and said it could be due to a number of things, but that the important part was that the symptoms go away.

1. I've read on this board that you need to wait 5-6 days after an exposure for an accurate urine test. This was about 3 days. Does that still apply even when symptoms are present? In other words, should I trust the result or is this more likely a false negative?

2. Assuming it was not a false negative, is there anything that can or should be done at this time with the original sample after roughly 10 days? Is it possible and/or recommended to test it for more specific GCUs? Or is clearing up the symptoms all that matters?

3. I've also read here that such infections, while possible, are rare from oral sex. As such, I feel rather unlucky. Does any of this alter your view of the risk of insertive oral sex, especially as it relates to more serious conditions like HIV? Should I be concerned in this scenario?

Thank you.

Edward W. Hook M.D.
Edward W. Hook M.D.
19 months ago
Welcome to our Forum.  Thanks for your confidence in our service.  I'll be glad to comment. It sounds like you developed urethritis as the result of your oral exposure.  Like the clinician you saw, I would have thought you had gonorrhea and would have treated in the same way you were.  Your clinical response supports the diagnosis and I am suprised that your Gonorrhea urine test was negative.  There are two possible explanations.  One possibility it that, as you mention, you may have had a false negative test.  While this is possible, it is unlikely- the false positive rate for current tests is a small fraction of 1%.  In my opinion, it is more likely that your urethritis was caused by the meningococcus, aa bacterium closely related to gonorrhea which is relatively common in the throat and can cause symptoms quite similar to those of Gonorrhea.  In response to your specific questions:
1.  When symptoms are present, tests are reliable.  In addition, when we say that it may take up to five days for symptoms to occur, the is because of the somewhat slower onset for Gonorrhea.  
2.  Between your negative test and what sounds like a full response like a full response to the therapy your received, I suspect all if fine and doubt that there is much to be gained from additional testing.
3.  I would not be worried about HIV from your oral exposure.  As you mention, infections from oral sex are rare but they do occur.  I think you were unlucky.

I hope these comments are helpful.  EWH
19 months ago

Thank you for the reply.

To clarify, I meant to say NGU, not GCU. My apologies.

To follow up:

1.   1. You state that you are surprised that the gonorrhea results turned up negative. If I recall properly, the doctor was leaning towards chlamydia, as that is more prevalent in the heterosexual community. Do I have that backwards? In any event, the doctor never even visually examined the discharge (even though I offered and showed her the underwear stains). I feel like once I mentioned the symptom(s) all she cared about was getting a urine sample.

2. If this is indeed meningococcus, I have to admit I am more than a bit scared right now. Hopefully, this is because I am completely unfamiliar with the condition. My (very) quick research, however, associates this strain with meningitis and sepsis, conditions I understand to be potentially fatal. Please help me understand what I am missing. Are we talking about two different things? 

Edward W. Hook M.D.
Edward W. Hook M.D.
19 months ago
Your clinical presentation was more consistent with a gonorrhea-like infection than with NGU.  That said, I explained the two main reasons your tests might have been negative.  I will also point out that the azithromycin that you took is recommended therapy for NGU as well.  As for your follow-up questions:
1.  Professionally, I'm disappointed the doctor did not examine you but she did the right tests.  You are correct, chlamydia is more common than gonorrhea however gonorrhea is not particularly uncommon (there will be over half a million new cases reported this year) and the description you provided ("yellow/green spots on my underwear and thick discharge from my penis") is more consistent with gonorrhea.  

2.  I fear that your "research" means you went to the internet and were mislead.   Meningococcal infections are complex.  The meningococcus and gonococcus have over 98% identical DNA but the difference in genetic material shifts the PROPORTIONS of the way infections present - the meningococcus can colonize the throat of people normally 9and does in about 1 out of 20 people), can cause a clinical syndrome very similar to gonorrhea (as I hypothesize it did for you) and rarely can cause sepsis and meningitis.  Do not be mislead by the internet and, most importantly as I tried to explain above, please appreciate that you responded well to therapy.  

As I said above, given your (negative) test results and your excellent response to therapy, my sincere advice is to not worry and to not seek further testing.  You are going to be fine.  EWH
19 months ago
Thank you Dr Hook.

After reading this forum non-stop for several days, my anxiety eventually went into overdrive. (I have struggled with anxiety/depression for about 20 years, but thought I had it under control.) It had been several years since my last test, but I had only engaged in what I think you'd describe as no risk or virtually zero risk behavior; ie protected intercourse and unprotected oral.  Prior to last month, the previous encounter was over a year ago.  The riskiest exposure was probably one time when the condom slipped upon withdrawal, but still remained on my penis and covered the urethra. In total, there were probably 10-12 encounters, with about 8-9 being with "high end" escorts.
Anyway, I managed to convince myself that I contracted HIV due to the accumulation of low/no risk exposures, so I went to a clinic for a test. This was only day 18 however, and I knew I couldn't wait another 3-4 weeks given the anxiety I had developed. The doctor ordered tests for HIV, syphilis, and Hep C, and I was told I'd be getting the "most accurate" test possible. The tests all came back negative, so I can obviously put to rest any doubts about past exposures. However, the HIV test was only for "HIV 1/2 antibody", so not the 4th generation "most accurate" I was expecting. 
1. Does this test hold any validity at 18 days for the recent encounter which resulted in NGU? I was hoping for the 75-80% accuracy of the 4th generation test that I've read about on this forum, but I'm guessing that's not happening now. 
2. Assuming it's useless for the recent oral exposure, (which I know you already said to not be concerned with) is further testing warranted?  In other threads, you've indicated that it's not medically recommended, but wouldn't be a bad idea if it helped ease anxiety and worry.  My anxiety is much better at the moment now that I've put past exposures to rest.
3. The syphilis and Hep C were the doctor's suggestions, and I'm guessing those are also useless after only 18 days?  That does not really concern me given what you've said elsewhere about how rare they are is in the heterosexual world, especially from oral sex, and the lack of symptoms.

Thank you and best regards.

Edward W. Hook M.D.
Edward W. Hook M.D.
19 months ago
I understand your desire to resolve your concerns with test results.  Unfortunately, the doctor you spoke with was not familiar with the performance of the tests he ordered. Since this is the end of this thread.I'll work through the tests one-by-one.

I've already told you that your test results for gonorrhea and chlamydia were reliable. That remains the case.

An antibody test for HIV would detect less than half of recent infections at 18 days.  A 4th generation, combination HIV antigen antibody test would do better, detecting over half of recent infections.  An HIV RNA PCR would be virtually conclusive at this time.  

Hepatitis C, like HIV is not transmitted through oral sex.  Test results however would not be conclusive until 4-6 weeks.

Similarly, a syphilis blood test would be meaningful at 4 weeks, not 18 days.

As you suggest, to be honest, I see no medical or scientific need for further testing.

I hope this information is helpful.  Please try your best not to worry about your recent very low risk encounter.  As mentioned above, as this is my 3rd reply to your questions, this will conclude this thread.   Take care.  EWH